I forgot to mention that on my last post that my son's diet has suddenly improved as well.
One day he was playing games on computer using the ZAC browser.
While he was occupied listening to music, my wife slowly slipped him some spaghetti with pasta containing minced mutton - something he had always rejected. He opened his mouth, tasted it, stopped for a while and started chewing. He then asked for more - of course non verbally. In the end, the whole bowl was empty.
My wife was nearly crying because this was the first time he was ever eating meat in a long long time. In fact we can't remember the last time he actually ate meat.
I am vegetarian but I am happy as well to see that he's willing to try different dishes.